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The influence of sunspot number on high frequency radio propagation

Malik, R. A. and Abdullah, M. and Abdullah, S. and Homam, Mariyam Jamilah (2014) The influence of sunspot number on high frequency radio propagation. In: 2014 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE 2014), 8 - 10 December 2014, Johor Bahru, Johor, Malaysia.


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This paper aims to study the influence of sunspot number on High Frequency (HF) radio communications in Peninsular Malaysia for the years 2009 to 2011. Sunspots, which are a natural phenomenon that occurs due to magnetic activities on the Sun’s surface, can be counted using smoothed sunspot number (SSN). HF signal propagates through the ionosphere where the ionospheric properties have been ionized by flares and prominences from sunspot number. This has significant effect on the stability of the ionosphere, resulting in the frequencies that can be used for HF communications to vary depending on the time of day, season, year and the 11-year solar cycle. This study was carried out during a period when the sunspot values rose from a low level in 2009 to a much higher level in 2011, making it suitable to observe the influence of sunspot number values on the HF frequencies employed. Maximum Usable Frequency (MUF) was determined based on HF transmission tests that were conducted from April 2009 to September 2011. It was observed that as the SSN values increase, the range of the operating HF frequencies and the numbers of frequencies that can be used also increase. This will, therefore, affect the median frequency that can be used for daily and monthly HF communications

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: high frequency; maximum usable frequency; radio propagation; ionosphere; sunspot number
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK6540-6571 Radio
Divisions: Faculty of Electrical and Electronic Engineering > Department of Communication Engineering
Depositing User: Mrs. Nurhayati Ali
Date Deposited: 16 Mar 2015 07:55
Last Modified: 16 Mar 2015 07:55
URI: http://eprints.uthm.edu.my/id/eprint/6695
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